TPS22997: Maximum slew rate setting of CT pin

Ben Kuo

Part Number: TPS22997

Tool/software:

Hi Team,

Does TPS22997 have maximum value of rise time(CT)?

Per my understood, slew rate control internal FET fully turn on speed. Not sure if we can connect large capacitor at CT pin for slower turn on application.

If this is a risk, what is maximum CT value and how to calculate it?

Regards,

Ben

2 months ago

0 Amrit Jit 2 months ago

TI__Genius 9026 points

Hello Ben,

You can use equation-1 and section 9.2.2 in datasheet to calculate CT value.

CT is used for inrush current control for output capacitor. It has been validated and characterized based on that.

Thanks

Amrit

0 Ben Kuo 2 months ago in reply to Amrit Jit

TI__Expert 7415 points

Hi Amrit,

So the maximum capacitor will be same as datasheet table in section 9.2.2?

Regards,

Ben

0 Amrit Jit 2 months ago in reply to Ben Kuo

TI__Genius 9026 points

Hello Ben,

There is no mention for maximum CT capacitor.

It's selected based on COUT.

Thanks

Amrit

0 Ben Kuo 2 months ago in reply to Amrit Jit

TI__Expert 7415 points

Hi Amrit,

Could you help to confirm below application?

Cout=24.9uF

CT = 15nF , rise time = 10.02ms

VIN/VOUT = 5V

IOUT = 0.13A

Thanks.

0 Amrit Jit 2 months ago in reply to Ben Kuo

TI__Genius 9026 points

Hi Ben,

Can you test it on EVM from your side?

Thanks
Amrit

0 Ben Kuo 2 months ago in reply to Amrit Jit

TI__Expert 7415 points

Hi Armit,

We don't have EVM, and RD is designing 22997 and colayout with competitor. If 22997 may have risk, I will promote other TI parts.

Ben

0 Amrit Jit 1 month ago in reply to Ben Kuo

TI__Genius 9026 points

Hello Ben,

I can verify from LAB. It may take some time. I will update by early next week.

Thanks

Amrit

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TPS22997: Maximum slew rate setting of CT pin